phpDocumentor/TypeResolver is a PHP library that parses PHPDoc type expressions (PSR-5) and resolves them into an object-oriented type system. It provides two main resolvers: TypeResolver, which converts a type string like 'string|int[]' into a tree of Type value objects (e.g., Compound, Array_, String_), and FqsenResolver, which resolves relative Fully Qualified Structural Element Names (FQSENs) to absolute ones using namespace context. The library leverages phpstan/phpdoc-parser for tokenizing and parsing the type syntax, then maps the AST to its own immutable type hierarchy. A ContextFactory extracts namespace and use-import information from PHP source code via token_get_all, enabling accurate resolution of relative class names. The type system covers primitives, compound types (unions, intersections), generics, callable signatures, array shapes, conditional types, integer ranges, and many pseudo-types (class-string, numeric, etc.). The library is a foundational component for phpDocumentor and other static analysis tools.